Driving mechanism for rotary gramophone turn or supporting plates.



No. 705.636. Patented My 29, I902. T. BIRNBAUM.

DBIVIIIG IEOIIANISI FDR ROTARY GRAIIOPHONE TURN 0R SUPPORTING PLATES.

(Application flied Oct. 19, 1901.) (In Model.)-

UNITED STATES THEODORE BIRNBAUM,

- PATENT OFFICE.

OF BERLIN, GERMANY.

DRlV iNG MECHANISM FOR ROTARY GRAMOPHONE TURN OR SUPPORTING PLATES.

SPECIFICATION forming part of Letters Patent No. 705,636, dated July 29,1902.

Application filed October 19,1901. Serial No: 79,251. (No model.)

To to whom it may concern.-

Be it known that I, THEODORE BIRNBAUM, managing director, a subject ofthe King of Great Britain and Ireland, residing at 36 Ritterstrasse, inthe city of Berlin, in the German Empire, have invented certain new anduseful Improvements in Driving Mechanism for Rotary Gramophone Turn orSupporting Plates, of which the following is a specification.

This invention has reference to means for operating gramophones, and inparticular to a stopping device by means of which the gramophone turn orsupporting plate is disengaged from the operating mechanism, so as to beable to arrest the said gramophone turnplate, which acts as a supportfor the recordplate of the gramophone.

The nature of the improvement consists in so arranging the drivingmechanism for the operation of the gramophone turn-plate that the saidmechanism is capable of rotation about a horizontal axis, the rotatingmovement causing the driving mechanism to become uncoupled from therotary gramophone turn-plate.

The nature of my invention will be better understood from theaccompanying diagrammatic sketch.

a is the gramophone turn-plate, capable of rotary movement and pivotallyjournaled in the usual manner upon the vertical shaft b. Below the saidgramophone turn-plate is a casing c, which contains the drivingmechanism, which is operated either by electricity or by spring actionand which causes the rotation of the driving-shaft d, upon the upperextremity of which I mount a friction-disk e, contacting with the rimfof the gramophone turn-plate. Thus if the shaft (Z is rotated thegramophone turn-plate a will also be revolved by means of thefriction-disk c.

It will be seen from the drawing that the driving mechanism is pivotedat 9 upon screws or bolts. A spring 72, at the opposite side has thetendency of raising the casing c for the driving mechanism, therebyforcing the friction-disk 6 against the rim f of the gramophoneturn-plate a. This arrangement is necessary, so as to insure sufficientfriction between the friction-disk c and the rim f of the rotarygramophone turn -plate and to transmit the rotation of the shaft (1 uponthe rotary gramophone turn-plate a. In order to stop the movement of thegramophone turnplate, it becomes only necessary to depress the casing cby means of a handle 1', forinstance, against the upward pressure of thespring, thereby removing the friction -disk e from contact with the rimf and stopping the gramophone-plate in its rotary move ment. Thisdownward movement of the easingcand its rotation about the axisg mayalso be easily combined with means for arresting the driving mechanismboth whether the source of movement is derived from electricity or fromspring action. In the latter case of a spring-actuated motor I may, forinstance, make use of a suitably-arranged ratchet-pawl which engageswith the moving gear of the said driving mechanism. If a motor driven byelectricity furnishes the power for operating the gramophone, thedescending movement of the casing may be employed to actuate an electricswitch or cutout in any simple and well-known manner. Simultaneouslywith the disengagement of the friction-disk with the rim f of thegramophone turn or supporting plate a bral e-shoe 7; may be forcedagainst the outside rimf of the said gramophone turn-plate, so as tocause an absolute stoppage of the gramophonc turnplate at the moment ofinterrupting the contact between the disk e and the rim, as otherwisewithout the application of a brake the gramophone-disk would stillcontinue to move for a short distance, owing to its momentum, after thedriving mechanism itself is stopped. The brake-shoe 7t is preferablyattached to an arm Z, attached to the casing 0, so as to operate thebrake 7t simultaneously with the disengagement of the fricton-disk c.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is-

1. In an actuating mechanism for a rotatable supporting-plate, thecombination with such plate, of a casing pivotally supported at oneside, a driven shaft (1 journaled in the casing, a friction disk carriedby the shaft and adapted to engage the plate, and a springsupport forthe casing opposite its pivotal support normally tending to force thedisk into engagement with the plate, substantially as set forth.

2. In an actuating mechanism for a rotatable supporting-plate, thecombination with such plate, of a casing pivotally supported at oneside, a driven shaft (1 journaled in the casing, a friction-disk carriedby the shaft and adapted to engage the plate, a springsupport for thecasing opposite its pivotal support normally tending to force the diskinto engagement With the plate, and a brakeshoe carried by the casingand normally out of engagement with said plate, said brakeshoe beingsupported to engage the plate when the casing is rocked on its pivot todisengage the disk from the plate, substantially as set forth.

In witness whereof I have hereunto signed my name in the presence of twosubscribing Witnesses.

THEODORE BIRNBAUM. lVitnesses:

WOLDEMAR HAUPT, HENRY HASPER.

